{ "title":"async attribute for external scripts", "description":"The boolean async attribute on script elements allows the external JavaScript file to run when it's available, without delaying page load first.", "spec":"https://html.spec.whatwg.org/multipage/scripting.html#attr-script-async", "status":"ls", "links":[ { "url":"https://developer.mozilla.org/en/HTML/Element/script#Attributes", "title":"MDN Web Docs - Script attributes" }, { "url":"http://ie.microsoft.com/testdrive/Performance/AsyncScripts/Default.html", "title":"Demo" }, { "url":"https://raw.github.com/phiggins42/has.js/master/detect/script.js#script-async", "title":"has.js test" }, { "url":"http://www.growingwiththeweb.com/2014/02/async-vs-defer-attributes.html", "title":"async vs defer attributes" } ], "bugs":[ ], "categories":[ "DOM", "HTML5" ], "stats":{ "ie":{ "5.5":"n", "6":"n", "7":"n", "8":"n", "9":"n", "10":"y", "11":"y" }, "edge":{ "12":"y", "13":"y", "14":"y", "15":"y", "16":"y", "17":"y" }, "firefox":{ "2":"n", "3":"n", "3.5":"n", "3.6":"y", "4":"y", "5":"y", "6":"y", "7":"y", "8":"y", "9":"y", "10":"y", "11":"y", "12":"y", "13":"y", "14":"y", "15":"y", "16":"y", "17":"y", "18":"y", "19":"y", "20":"y", "21":"y", "22":"y", "23":"y", "24":"y", "25":"y", "26":"y", "27":"y", "28":"y", "29":"y", "30":"y", "31":"y", "32":"y", "33":"y", "34":"y", "35":"y", "36":"y", "37":"y", "38":"y", "39":"y", "40":"y", "41":"y", "42":"y", "43":"y", "44":"y", "45":"y", "46":"y", "47":"y", "48":"y", "49":"y", "50":"y", "51":"y", "52":"y", "53":"y", "54":"y", "55":"y", "56":"y", "57":"y", "58":"y", "59":"y", "60":"y", "61":"y" }, "chrome":{ "4":"n", "5":"n", "6":"n", "7":"n", "8":"y", "9":"y", "10":"y", "11":"y", "12":"y", "13":"y", "14":"y", "15":"y", "16":"y", "17":"y", "18":"y", "19":"y", "20":"y", "21":"y", "22":"y", "23":"y", "24":"y", "25":"y", "26":"y", "27":"y", "28":"y", "29":"y", "30":"y", "31":"y", "32":"y", "33":"y", "34":"y", "35":"y", "36":"y", "37":"y", "38":"y", "39":"y", "40":"y", "41":"y", "42":"y", "43":"y", "44":"y", "45":"y", "46":"y", "47":"y", "48":"y", "49":"y", "50":"y", "51":"y", "52":"y", "53":"y", "54":"y", "55":"y", "56":"y", "57":"y", "58":"y", "59":"y", "60":"y", "61":"y", "62":"y", "63":"y", "64":"y", "65":"y", "66":"y", "67":"y" }, "safari":{ "3.1":"n", "3.2":"n", "4":"n", "5":"a #1", "5.1":"y", "6":"y", "6.1":"y", "7":"y", "7.1":"y", "8":"y", "9":"y", "9.1":"y", "10":"y", "10.1":"y", "11":"y", "11.1":"y", "TP":"y" }, "opera":{ "9":"n", "9.5-9.6":"n", "10.0-10.1":"n", "10.5":"n", "10.6":"n", "11":"n", "11.1":"n", "11.5":"n", "11.6":"n", "12":"n", "12.1":"n", "15":"y", "16":"y", "17":"y", "18":"y", "19":"y", "20":"y", "21":"y", "22":"y", "23":"y", "24":"y", "25":"y", "26":"y", "27":"y", "28":"y", "29":"y", "30":"y", "31":"y", "32":"y", "33":"y", "34":"y", "35":"y", "36":"y", "37":"y", "38":"y", "39":"y", "40":"y", "41":"y", "42":"y", "43":"y", "44":"y", "45":"y", "46":"y", "47":"y", "48":"y", "49":"y", "50":"y", "51":"y", "52":"y" }, "ios_saf":{ "3.2":"n", "4.0-4.1":"n", "4.2-4.3":"n", "5.0-5.1":"y", "6.0-6.1":"y", "7.0-7.1":"y", "8":"y", "8.1-8.4":"y", "9.0-9.2":"y", "9.3":"y", "10.0-10.2":"y", "10.3":"y", "11.0-11.2":"y", "11.3":"y" }, "op_mini":{ "all":"n" }, "android":{ "2.1":"n", "2.2":"n", "2.3":"n", "3":"y", "4":"y", "4.1":"y", "4.2-4.3":"y", "4.4":"y", "4.4.3-4.4.4":"y", "62":"y" }, "bb":{ "7":"y", "10":"y" }, "op_mob":{ "10":"n", "11":"n", "11.1":"n", "11.5":"n", "12":"n", "12.1":"n", "37":"y" }, "and_chr":{ "64":"y" }, "and_ff":{ "57":"y" }, "ie_mob":{ "10":"y", "11":"y" }, "and_uc":{ "11.8":"y" }, "samsung":{ "4":"y", "5":"y", "6.2":"y" }, "and_qq":{ "1.2":"y" }, "baidu":{ "7.12":"y" } }, "notes":"", "notes_by_num":{ "1":"Using script.async = false; to maintain execution order for dynamically-added scripts isn't supported in Safari 5.0" }, "usage_perc_y":94.67, "usage_perc_a":0.02, "ucprefix":false, "parent":"", "keywords":"", "ie_id":"", "chrome_id":"", "firefox_id":"", "webkit_id":"", "shown":true }